This invention relates to the field of surgeries conducted through a tubular guide or cannula, including but not limited to arthroscopic, endoscopic, laparoscopic, thoracoscopic, and intravascular surgeries. In particular, this invention relates to instruments insertable through a cannula and carrying a surgical fastener to a distal end thereof. This invention also relates to a method for clamping organic tissues.
Various minimally invasive surgical techniques have been developed involving the passage of instruments down a tubular guide or cannula inserted into an existing orifice or duct of the human body, penetrating a bodily wall, or both. These techniques include, but are not limited to, arthroscopic, endoscopic, laparoscopic, thoracoscopic, and intravascular surgeries, although in laparoscopic surgery the tubular penetration may be limited to the bore of a trocar sleeve, an extended cannula being omitted. In these techniques, space, and in particular space perpendicular to a longitudinal or major extensive axis of a surgical instrument designed for insertion through a cannula, is at a premium. Devices which may be collapsed along one or two dimensions, opening to a full extension inside a patient and mechanisms allowing a compact insertion of an otherwise prohibitively large surgical device, will therefore find utility in minimally invasive techniques.
Positively or self-locking surgical clamps, such as those intended for occlusion of a sperm duct, occupy less space in a lateral dimension relative to a major axis of the clamp in a closed configuration than in an open configuration. However, by the very positive locking feature, i.e., by virtue of having a locking mechanism which permanently holds the clamp closed once the jaws are engaged, a clamp of this variety so closed cannot be conveniently opened. Holding such a clamp in a partially closed pre-firing configuration during an insertion is one method of reducing lateral space requirements. However, in order to achieve a maximum pre-firing compactness in a lateral dimension, a self-locking clamp would be ideally inserted in an essentially fully closed configuration, without thereby engaging the locking mechanism.
It is an object of the present invention to provide an instrument for use in minimally invasive surgical procedures.
It is a more particular object of this invention to provide a surgical clamping instrument adapted for insertion through a cannula, or other tightly confined opening.
Yet a more particular object of this invention is provide such a surgical clamping instrument for inserting a lockable surgical clamp in an essentially closed configuration pre-firing condition, without thereby engaging the locking mechanism.
An associated object of the present invention is to provide a method for clamping organic tissues in a surgical procedure.
An additional related object of the present invention is to provide such a method for particular use in minimally invasive procedures wherein surgical operations are effectuated through a narrow tubular guide or cannula.
These and other objects of the invention will become apparent through an inspection of the description and figures hereunder.
A insertion device for a surgical clamp or fastener in accordance with the present invention includes a set of jaws having at least one opened configuration and two closed configurations, the closed configurations comprising an in-line configuration and a skewed or off-set configuration. In the offset configuration, the jaws hold the fastener in a distorted essentially closed state so that locking elements on legs of the fastener do not engage one another, enabling the fastener to be opened upon insertion of the jaws and the fastener into a patient. In the in-line configuration of the jaws, the jaws close the fastener about intervening organic tissues of the patient, enabling engagement of the locking elements and a locked closure of the fastener.
Pursuant to another feature of the present invention, the jaws are placed in the offset configuration by a skew motion of at least one of the jaws, which may be defined as a rotation of the jaws about a secondary axis perpendicular to a rotation axis of a jaw hinge and also perpendicular to a longitudinal axis of the jaws: rotation about the longitudinal axis would alternatively constitute a relative torquing or twisting motion of the jaws.
Pursuant to one step of a method in accordance with the present invention, the jaws are disposed in an open configuration, pre-mounted with a self-locking clamp or fastener, and then closed into the in-line configuration, resulting in an engagement of locking elements on the fastener, and a permanent closure of the fastener. Subsequently opening the jaws disengages the jaws from the now set fastener and allows withdrawal of the device from an operating site. In contrast, closing the jaws in the offset configuration prevents an engagement of the locking elements, while still substantially closing the fastener. An ability to close the jaws without engaging the locking elements of a positively locking fastener allows the fastener to be first inserted through a narrow cannula or other limited aperture with substantial space savings. The jaws in general will have to be returned to a substantially closed position after disengaging or dismounting of the set fastener, to allow removal of the device through the same cannula.
It is apparent that it must be possible to close the jaws in a first or second closed configuration in a useful order. In a simplest method, an alternation of skew and in-line motions is realized on alternate closures. This alternating motion is achieved by one of two mechanisms or medical instruments pursuant to the present invention.
In a first mechanism or instrument, the instrument device has a lower jaw, rigidly mounted to a sheath or stalk defining a major longitudinal axis of the instrument. An accompanying upper jaw is attached to the lower jaw at a hinge or pivot point. The sheath serves as a guide for a drive rod or post, which is, at a distal tip of the instrument, is essentially constrained to move in parallel to the lower jaw. A linkage engaging the drive rod is connected to lower and upper jaws, and urges the jaws apart, in an opened configuration, when the rod is forced outward, in a distal direction, with respect to the sheath. Conversely, when the rod is withdrawn in an opposite the jaws are urged together into a closed configuration. A distal tip of the drive rod further engages a ratcheting mechanism mounted under the lower jaw, which in turn drives a control wheel mounted in an angle of the jaws, on the lower jaw, via a shaft. The ratcheting mechanism rotates the control wheel a fixed amount, 180xc2x0 in the present embodiment, upon each distal extension of the rod.
The control wheel is provided on an upper surface with two camming devices, which alternatively engage a wedge or tooth mounted on an under surface of the upper jaw. In a locking position of the wheel, a V-shaped guide receives the tooth and aligns the jaws to force an engagement of self-locking elements on a mounted surgical fastener upon closing of the jaws. In a skewing position of the wheel, a second wedge deflects the wedge or tooth on the upper jaw, causing a skewing motion of the jaws and preventing an engagement of the locking elements on the fastener. In this configuration, the jaws may be essentially closed, achieving a minimum lateral dimension, without positively locking an attached surgical fastener. In order to allow a desired range of motion of the jaws, a hinge having a pre-determined amount of mechanical xe2x80x9cslopxe2x80x9d or tolerance is employed, the V-shaped guide serving to effect a positive in-line closure in a first position of the wheel. Alternatively, a partial ball or universal joint may be employed.
In a second mechanism or instrument in accordance with the present invention, a substantially similar design of sheath, drive rod, hinge and jaws are utilized. However, the wheel and camming devices are eliminated. In their place a guide track is mounted on a lower surface of the lower jaw, engaging a substantially vertical pin projecting from a distal end of the drive rod. The track is comprised of two branches, which come together at a distal end thereof, meeting in a ratcheting or switching device. Upon each distal extension of the drive rod, the ratcheting device is engaged at an extreme of the motion, and alternatively redirects the rod into a first branch and a second branch of the track.
Upon engagement of the pin or projection in a first, straight, branch of the track, the jaws are drawn together in-line upon a withdrawal of the drive rod, effectuating engagement of locking elements of an attached surgical fastener. Alternatively, upon engagement of the pin in a second, curved, branch of the track, the drive rod is forced out of alignment with respect to the lower jaw and longitudinal axis of the instrument, and the upper jaw, is compelled by a bending of the rod, via the linkage engaging the rod and the jaws, out of alignment with the lower jaw, and thereby closes in an offset configuration.
An additional degree of mechanical tolerance is included in the linkage in the second embodiment relative to the first embodiment, to allow a bending motion of the rod to be translated to a skew motion of the jaws. Alternatively, partial universal joints are employed in the linkage.
An instrument in accordance with the present invention enables the application of a surgical clip or fastener to internal tissues of a patient via a natural or surgically formed opening in the patient which is substantially smaller than the opened configuration of the clip or fastener.